I know this seems odd saying "children over 18 yrs of age"..
The problem is, a friend of ours has a posting here. He has two kids, both over 18 years of age.. they would be coming along. They do not work, so technically not dependents. But it seems that China visa is not available for children over 18 yrs of age, since they wouldnt be dependents ? Is this true ? Then what would be the course of action ? Take a tourist visa with round trip ticket ( visa will be given only on round trip ticket ??) and then come here and then change it ?
I tried searching through the forum but couldnt find the appropriate one, so sorry if this has been asked before.
Thanks.

Yeah thats exactly right just come on a tourist visa and then apply for a business visa with your friends company sponsoring them (If they have a registered capital over 5 million)or just paying more and having an agency do it.